The present invention relates to an improved enclosure, more specifically to an improved metal enclosure for holding electrical components and the like providing a sealed environment in the interior of the enclosure.
Enclosures for electrical components and the like are well-known in the art. However, these known enclosures have been unable to meet the needs and requirements of the marketplace. It has been reported that among the most important of the several factors which are dramatically changing the manner in which enclosure manufacturers satisfy the needs of high-tech industries in the '90s is the overall aesthetic appeal of the enclosure. The cabinet is not simply an outside for a company's electronic insides, it is a major aesthetic marketing tool and an important equipment protection and isolation device. It has been stated that appearance continues to be a very important consideration in cabinet design, with current trends leaning toward a more ergonomic look. Recent studies of enclosure users have reported a desire for a cleaner look, including a reduction of visible seams, a blending of exposed hardware into the overall design and a switch to hidden hinges. See Jay R. Manwaring, Product Design and Development, "Enclosures", Pages 21-23 (Nov. 1991).
The presently existing enclosures often utilize an exterior piano type hinge or exterior mounted pin and sleeve hinges that allow the cover to be lifted off. These exterior mounted hinges have the advantage of being easy to design and assemble; however, they interrupt the continuous line on the exterior of the enclosure disrupting the overall aesthetic quality of the enclosure. Furthermore, these exterior hinges protrude from the side of the enclosure creating an extension upon which clothing, tools, machinery and the like may become caught or snagged.
Interior hinges have also been utilized in enclosures for electrical components and the like. However, internal hinges have limited the range of motion of the door. Due to this limited range of motion of the door, access to the interior of these enclosures with internal hinges is somewhat restricted.
Other enclosures have been designed to alleviate these problems by eliminating hinges altogether. The door, or lid, is merely positioned and latched onto the enclosure body. This arrangement has proved unsatisfactory because upon opening the enclosure the removed door portion must be placed somewhere, and there is not always an appropriate place to temporarily store the removed door portion, nor is it convenient for the user to hold the door while operating in the interior of the enclosure. Furthermore, since the door is not attached to the enclosure, it becomes possible to misplace the door. The interior of enclosure doors have been utilized as a valuable mounting and storage location for tools, spare parts and equipment. A removable hingeless door eliminates this as a practical location for article storage.
The doors of enclosures for electrical components and the like include a sealing gasket to provide a sealed environment in the interior of the enclosure. The prior art enclosures most commonly utilize a neoprene gasket. A neoprene gasket is formed from several strips of neoprene placed around the periphery of the sealing surface. Generally, a reinforcing structure is provided to help maintain the neoprene gasket in position as well as to adequately locate the intended position of the neoprene gasket. The reinforcing structure can be a flange spot welded to the door or a groove formed in the door in which the neoprene gasket will be positioned. Neoprene gaskets have several drawbacks. Adjacent strips of the neoprene gasket must be positioned with tight tolerances and further sealed to eliminate seepage through this joint. Neoprene gaskets tend to acquire a compression set over time, meaning that the gasket will begin to take the shape of the sealing surface in which it is clamped against during an unclamped state. Consequently, through continued use, the clamping force needed to seal the door will have to be increased to obtain the required seal.
Silicone gaskets have also been utilized in providing sealing for enclosures. Silicone provides the advantage that it can be positioned in a continuous bead. However, silicone provides a relatively hard sealing gasket, takes longer to cure than normally utilized neoprene gaskets and also tends to form a compression set over time. Due to the relative hardness and the compression set of the silicone gasket, a greater number of latches and higher clamping force are needed with enclosures using silicone gaskets.